A top mainland official in Hong Kong has launched a thinly veiled attack on the Occupy Central movement, saying that the city's "youth" are responsible for rejecting any action that will damage what he called "the rule of law".

The remark yesterday by Wang Zhimin, deputy director of the central government's liaison office, faithfully reflected Beijing's hardline stance against the civil disobedience plan proposed by University of Hong Kong law academic Benny Tai Yiu-ting as a last-ditch attempt to attain full democracy by 2017.

"Hong Kong is now at a crucial moment in its economic and democratic transition," Wang said in the opening speech of an anniversary event for Beijingloyalist group the Hong Kong United Youth Association. "It is the responsibility of the youth to treasure and safeguard Hong Kong's stability and to reject and prevent chaos that will damage and trample on the rule of law."

Wang added that the central government was content with the city's governance under Chief Executive Leung Chun-ying.

He called on young people to "stay united" and become "a new force" to support Leung, but he also said that some younger people had complaints that society should address.

On Tuesday, National People's Congress Chairman Zhang Dejiang said the central government firmly supported Leung and his government, the first such remark since this year's July 1 rally.

Zhang was also quoted as saying that "the rule of law is key" to improving livelihoods and to carrying out democratic reform.